Bowel cancer risk potentially lowered through exercise

bowel cancer risk
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Scientists at Newcastle University have identified that bowel cancer risk can be reduced through exercise in a groundbreaking discovery.

The University researchers have demonstrated that interleukin-6 (IL-6), a protein that effectively combats cancer, is released into the bloodstream during physical activity, helping repair the DNA of damaged cells. The study discovered that exercise does not only lower bowel cancer risk but also can mitigate the growth of tumours.

The research highlights the benefits of moderate activity for reducing the chances of life-threatening illnesses and may help to design novel treatments. The study’s findings have been published in the International Journal of Cancer.

Dr Sam Orange, Lecturer in Exercise Physiology at Newcastle University, said: “Previous scientific evidence suggests that more exercise is better for reducing bowel cancer risk as to the more physical activity people do, the lower their chances of getting it. Our findings support this idea.

“When exercise is repeated multiple times each week over an extended period, cancer-fighting substances – such as IL-6 – released into the bloodstream have the opportunity to interact with abnormal cells, repairing their DNA and reducing growth into cancer.”

One of the biggest causes of mortality in the UK

Bowel cancer is the most common form of the disease in the UK, making up for 11% of all new cancer cases. This equates to around 42,900 people diagnosed with bowel cancer annually in the UK, which is approximately 120 each day.

Prior studies have suggested that exercise reduces bowel cancer risk by approximately 20% and can be performed by going to the gym, playing sports, active travel, such as walking or biking to work, or even household tasks like gardening or cleaning. However, exactly why physical activity may lower bowel cancer risk has remained unknown.

Reducing bowel cancer risk

To investigate this further, scientists performed a small-scale study including 16 men aged 50 to 80. All of the participants had lifestyle risk factors for bowel cancer, such as being overweight or obese, and not being physically active.

An initial blood sample was taken from the individuals, and then they cycled on indoor bikes for 30 minutes at a moderate intensity, with a second blood sample taken as soon as they finished pedalling.

On a different day, the researchers took more blood samples before and after the participants had rested, which served as a control. Next, tests were completed to see if exercise affected the concentration of cancer-fighting proteins compared to resting samples, which revealed that physical activity elevated IL-6 production.

The team added the blood samples to bowel cancer cells in a lab and analysed cell growth over 48 hours. The blood samples collected after exercise mitigated the growth of cancer cells compared to the samples collected at rest. In addition to alleviating cancer growth, the blood samples collected after exercise also reduced DNA damage, meaning physical activity could potentially repair cells to create a genetically stable cell type.

Dr Orange said: “Our findings are really exciting because they reveal a newly identified mechanism underlying how physical activity reduces bowel cancer risk that is not dependent on weight loss.

“Understanding these mechanisms better could help develop more precise exercise guidelines for cancer prevention. It could also help develop drug treatments that mimic some of the health benefits of exercise.

“Physical activity of any type, and any duration, can improve health and reduce bowel cancer risk, but more is always better. People who are sedentary should begin by moving more and look to build physical activity into their daily routines.”

Dr Adam Odell, Senior Lecturer in Biosciences from York St John University, concluded: “Importantly, it is not just bowel cancer risk that can be reduced by leading a more active lifestyle. Clear links exist between higher exercise levels and a lower risk of developing other cancers, such as cancers of the breast and endometrium.

“By working out a mechanism through which regular physical activity is able to produce anti-cancer effects, our study provides further support for current national and global efforts to increase exercise participation.”

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